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16 Answers

Banging noise from thermal expansion/contraction

My dwelling has cathedral ceilings and we have a problem with thermal expansion/contraction causing a "banging" noise after sunrise and at sunset. I have a high moisture reading in the morning and but the attic temperature is close to the outside temperature and by mid-day, the spread between the attic and outside increases to around 20 degrees and the moisture reading will goes from wet to dry. At the recommendation of 3 roofers, I had ridge vents added. The overhang is only about 10 inches but has vinyl venting all the way across. There is no venting on the side eves.

Asked By David Burns | Jul 27 16
2 Answers

Open cell foam contacting hot water heater flue

I have open cell foam being put into my attic. My hot water heater is in the garage below, but where the flue goes through the rafters, is it OK for the open cell foam to contact around the flue? If not, how much of a gap is left around it? I guess they would have to just cut that gap after foaming since the foam isnt going to just cooperate....

Asked By John Sexton | Jul 27 16
5 Answers

Choose Slightly Higher HSPF or save $ upfront as payoff is ~7 years.

I'm looking to buy a mini-split for my business office. Seems simple enough but I have 3 basic choices.
15 SEER 9 HSPF at base price for either 115v/230v, simple inverter
21.5 SEER 9.8 HSPF(IV) bp+$300 for 230v, upgraded inverter
21.5 SEER 11.2 HSPF(IV) bp+$320 for 115v, upgraded inverter
I've no problem installing 230v vs 115v and it's only 5' from the panel.

First, is it even worth paying the $300+ for about a $40/year savings? 9 vs 9.8 or 11.2,

Asked By Karl Koning | Jul 27 16
9 Answers

1903 home, first time with central air, lots of questions about insulating, ductwork, etc

Hello! Grab a cup of coffee and hopefully you will have a little insight on this! Thank you!!!!!!!!!!!!!!

I have an early 1900s 2 story victorian home 2200 sq ft, currently getting a new roof next month, and had to remove the old insulation on the attic floor that was outdated in roof preparation (in april). Blown in insulation was added to all exterior walls, as well as a thin sheet of foam fiberglass insulation, prior to installing vinyl siding over the wood siding about 25 years ago. Also storm windows to cover the old windows.

Asked By John Friend | Jul 25 16
0 Answers

Fiberglass Batts in a Cathedral Ceiling- Round 2

Thanks, Martin and Dana, for your timely responses and comments. My wife and I read the articles, "How to build an Insulated Cathedral Ceiling" and "Site-Built Ventilation Baffles for Roofs". The air-sealing of the site-built baffles sounded formidable and the mention of no known failures from the use of impermeable baffle materials was enough for us to consider using them. At this point in the construction, per your advice we have the ability to modify the cathedral ceiling insulation plan and propose the following:

Asked By Michael Watson | Jul 27 16
6 Answers

Minisplit retrofit in Climate Zone 2

I'm trying to figure out how to use a minisplit system on a retrofit project. I got a quote from an HVAC company (recommended by the equipment rep), but some of their opinions don't make sense...which brings me here today.

The HVAC company proposed 4 zones with a 3 Ton compressor outside:
1 ducted 9k unit in attic, serving Guest Bath, Guest Bed, and Office
1 ducted 9k unit in attic serving Master Bed and Bath
1 9k ductless serving kitchen
1 9k ductless serving living

Asked By Green Heron | Jul 26 16
8 Answers

Zone 6 dew point

Would a 2x6 wall with:
R-23 Roxul Batts in the cavity,

Exterior layers of:
OSB sheeting,
1" R-6 R Max rigid insulation (taped),
R-6 Insultex House Wrap (taped)
And finished with stucco,
eliminate the dew point problem in a Zone-6?

I called Insultex and they recommended their product be installed over the rigid insulation

Thanks,
Dave

Asked By David Dunn | Jul 27 16
13 Answers

Insulating a raised floor over an old concrete slab

Hi, I have a house in Seattle. The back portion of the house has a 60 year old 600 square foot slab with approximately 2' deep footers. The ground slopes gently away from the foundation, and the roof overhangs each side by about 2-3'. Let's assume there is no gravel, sand, plastic, or insulation underneath the slab. There is no plastic or insulation on the exterior perimeter of the foundation either. The foundation perimeter vertically extends approximately 1/2"-1" above the slab. While the perimeter is level, the concrete slab is uneven, hence the 1/2"-1" inch variance.

Asked By Jo Lee | Jul 8 16
15 Answers

Exterior walls to meet code without gypsum?

Hello,

Maybe this has been discussed here. Feel free to link me to other threads that I haven't seen if this is fully covered elsewhere.

I'm not a fan of drywall. A quick rundown with no real surprises: it used to be cheaper; now it's not. It also takes plenty of work and more money to make it look nice. It's heavy but also very breakable. Even when you don't break it, it's messy. Etc, etc. I *am* a fan of 3/4 plywood, which is less breakable, more durable, and looks nice.

Asked By Minneapolis Disaster, 6B | Jul 22 16
2 Answers

Closed-cell spray foam insulation under a sunporch

We installed 2 inches of spray foam closed cell insulation on the underside of a sun porch which is open on a sides underneath. My husband wants to store his riding lawn mower underneath which means he will have to drive it under the porch and start it up under the porch. I understand that this foam is highly flammable. Please advise if this is safe or what we can do to ensure safety of the storage of the riding mower. Thank you.

Denise P

Asked By Denise Phelps | Jul 27 16
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